I stand corrected on the engine start sequence as it is 3,4,2,1. It's a bit like the firing sequence of a four cylinder engine, I always mix it up! :D

If it is inboard engines first, why do we go from 3 to 4 and not 3 to 2? This would make the engine start 3, 2, 4, 1, or even 3, 2, 1, 4. Now if we were to use an engine start example from the C-130, it is 3, 4, 1, 2 and the start cart is right near the #2 props. Not a good place to on an engine start, so the idea is that by the time engine 2 gets started the cart (and ground crew) is well away. The cart is always there because the external connectors are on that side of the fuselage. Perhaps this same type of situation applies to the 707. Food for thought!

Mark